CVE-2023-52800 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix htt pktlog locking
The ath11k active pdevs are protected by RCU but the htt pktlog handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a read-side critical section.
Mark the code in question as an RCU read-side critical section to avoid any potential use-after-free issues.
Compile tested only.
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Analysis
by VulDB Data Team • 11/07/2024
The vulnerability CVE-2023-52800 affects the Linux kernel's ath11k wireless driver implementation, specifically addressing a concurrency issue within the High Throughput Transport (HTT) packet logging subsystem. This flaw exists in the handling of active physical device (pdev) management where the driver maintains a list of active wireless devices using Read-Copy-Update (RCU) synchronization mechanisms. The ath11k driver is responsible for managing Qualcomm's 802.11ac wireless chipsets and provides the necessary interface between the hardware and the Linux networking stack.
The core technical issue stems from improper RCU synchronization in the htt pktlog handling code path. When the function ath11k_mac_get_ar_by_pdev_id() is invoked to retrieve device information for packet logging purposes, the calling code does not properly mark this operation as an RCU read-side critical section. This omission creates a race condition scenario where the driver might access memory locations that have been freed or reallocated while the RCU grace period is still in progress. The lack of proper RCU read-side critical section annotation means that the kernel's RCU subsystem cannot guarantee that the referenced data structures remain valid during the execution of the packet logging code.
This vulnerability represents a classic use-after-free scenario that can lead to system instability and potential security implications within the wireless networking subsystem. The flaw occurs when multiple threads or contexts attempt to access the same physical device data structures simultaneously, with one thread potentially freeing memory while another thread is still reading from it. The consequences can manifest as kernel oops, system crashes, or in more severe cases, privilege escalation opportunities that could be exploited by malicious actors. The vulnerability directly relates to CWE-416, which describes use-after-free conditions in software systems, and aligns with ATT&CK technique T1059.007 for kernel-level exploitation.
The fix implemented addresses this issue by properly marking the htt pktlog handling code as an RCU read-side critical section, ensuring that the kernel's RCU subsystem correctly manages the synchronization requirements for accessing the active pdevs data structures. This change prevents potential race conditions that could lead to memory corruption and system instability. The mitigation approach follows established kernel development practices for RCU synchronization and aligns with the Linux kernel's recommended patterns for protecting shared data structures. The vulnerability affects systems running Linux kernels with the ath11k driver, particularly those utilizing Qualcomm-based wireless hardware in enterprise or consumer networking environments. While the fix has been compile-tested, deployment should include thorough regression testing to ensure no unintended side effects occur in wireless networking functionality. The resolution demonstrates the importance of proper synchronization mechanisms in kernel space programming and highlights the critical nature of RCU usage patterns in concurrent systems.